The leaflets of the human mitral and tricuspid valves help establish an orderly pattern of blood flow into the left and right ventricles. For example, the anterior leaflet of the mitral valve extends diagonally across its ventricular cavity, separating it into inflow and outflow tracts. The resulting flow pattern in the left ventricle consists of vortices that aid in cleansing the ventricular cavity and in closing the valve such that little, if any, regurgitation occurs upon contraction of the ventricle.